This invention relates to racks for holding sample tubes, and more particularly to a sample tube rack for automatic transport of a plurality of sample tubes to be unloaded at the receiving area of a sample analysis system, and later reloaded at an exit area of the sample analysis system for removal.
High volume testing of body fluids, such as blood samples, is usually carried out in an automatic sampling system for sample analysis. The automatic sampling system, which operates with a minimum of human intervention, automatically withdraws samples from a sample tube in selected amounts for automatic testing and analysis. The test apparatus in known automatic sampling systems are generally adapted to perform one or more specific tests or a battery of tests on discrete amounts of sample that are withdrawn from a sample tube.
In some instances it is desirable to transport the sample tubes to the receiving area of the sample analysis system in one type of sample tube rack, and then transport the sample tubes within the automatic analysis system in another type of sample tube rack. Whenever a sample tube is transferred from one sample tube rack to another sample tube rack there must be stability of the rack during the transfer process. It is also important that the sample tubes in the rack be held with sufficient retention force to maintain stability of the tubes in the rack during their journey from one point to another. However, any retention force applied to the sample tubes in the rack should also permit easy release for unloading of tubes from the rack and easy installation of the sample tubes into the rack when it is reloaded after testing of the samples in the sample tubes is completed.
It is also beneficial that the rack be able to accommodate sample tubes of different length and diameter without adversely affecting the loading and unloading facility of the rack.
It is thus desirable to provide a sample tube rack that can be easily constructed and assembled for automatic transport at relatively high speeds while maintaining stable accommodation of the sample tubes in the rack during such transport.